Exams and Tests for a Herniated Disc
Physical Exam, X-rays, CT Scans, and MRIs to Diagnose a Herniated Disc
As you likely know, a herniated disc can cause pain and interrupt your daily activies. That's most likely what brings you into the doctor's office: you have back pain or neck pain, and you'd like to know why. Your doctor will ask you questions and perform some exams. This is to try to locate the source of your pain and to figure out which intervertebral discs are herniated. An accurate diagnosis will also help your doctor develop a treatment plan for you—a way to manage your herniated disc pain and other cervical and lower back symptoms and to help you recover overall.
Physical Exam: Step One in the Herniated Disc Diagnosis
As part of the physical exam, your doctor will ask about your current symptoms and remedies you have already tried for your pain.
Typical Herniated Disc Diagnostic Questions
- When did the pain start? Where is the pain (cervical, thoracic or mid-back, or lumbar or lower back)?
- What activities did you recently do?
- What have you done for your herniated disc pain?
- Does the disc herniation pain radiate or travel to other parts of your body?
- Does anything reduce the disc pain or make it worse?
Your doctor will also observe your posture, range of motion, and physical condition both standing and lying down. Movement that causes pain will be noted.
A Laségue test, also known as the Straight-Leg Raising test, may be done. You will be asked to lie down and extend your knee with your hip bent. If it produces pain or makes your pain worse, this may indicate a herniated disc.
With a herniated disc (or a bulging or ruptured disc), you may feel stiff and may have lost your normal spinal curvature due to muscle spasm. Your doctor will feel your spine, note its curvature and alignment, and feel for tightness.
Your spine specialist will also conduct a neurological exam, which tests your reflexes, muscle strength, other nerve changes, and pain spread.
Radicular pain (pain that travels away from the source of the pain) may increase when pressure is applied directly to the affected area. You may, for example, have sciatica (leg pain); that is radicular pain that may be caused by the herniated disc. The source of the pain is in your spine, but because the herniated disc is pressing on a nerve that's travelling to your leg, you may have radicular pain.
Imaging Tests for Herniated Discs
Your spine specialist may order imaging tests to help diagnose your condition; you may need to visit an imaging center for these tests.
An x-ray can show a narrowed disc space, fracture, bone spur, or arthritis, which may rule out disc herniation.
A computerized axial tomography scan (a CT or CAT scan) or a magnetic resonance imaging test (an MRI) both can show soft tissue of a bulging disc. These tests will show the stage and location of the herniated disc so you can receive proper treatment.
Other Tests to Diagnose a Herniated Disc
To obtain the most accurate diagnosis, your spine specialist may order additional tests, such as:
- Electromyography (EMG): If your spine specialist suspects you have nerve damage, he or she may order a test called an electromyography to measure how quickly your nerves respond.
- Discogram or discography: A sterile procedure in which dye is injected into one of your vertebral disc and viewed under special conditions (fluoroscopy). The goal is to pinpoint which disc(s) may be causing your pain.
- Bone scan: This technique creates computer or film images of bones. A very small amount of radioactive material is injected into a blood vessel then throughout the blood stream. It collects in your bones and can be detected by a scanner. This procedure helps doctors detect spinal problems such as arthritis, a fracture, tumor, or infection.
- Lab tests: Typically blood is drawn (venipuncture) and tested to determine if the blood cells are normal or abnormal. Chemical changes in the blood may indicate a metabolic disorder which could be contributing to your back pain.